1. Field of the Invention
The present invention relates to kickback-inhibiting component for cutting devices. More specifically, the present invention relates to kickback-inhibiting devices for inhibiting workpieces from being lifted up by the impact force produced though contact with the cutting blades of cutting devices, such as table saws, which cutting blades may still be rotating at a high speed immediately after the workpieces have been cut.
For example, table saws have a circular saw blade that partly extends upward from a table on which workpieces are to be placed. Moving the workpiece along the table relative to the saw blade may perform the cutting operation. In the case of table saws, or with cutting devices in which the cutting operation is performed in the same manner as with table saws, the cutting blade (e.g., saw blade) rotates such that the front side of the cutting blade (with respect to the moving direction of the workpiece during the cutting operation) moves downward while the rear side of the cutting blade moves upward. Therefore, if the workpiece contacts with the rear side of the rotating cutting blade immediately after forming the kerf (i.e., immediately after cutting the workpiece), the workpiece may possibly be lifted up or kicked back by the rotating cutting blade. When this occurs, it is difficult to perform a smooth cutting operation.
Therefore, there has been proposed to provide a flat plate (which may be called a “riving knife”) that has a thickness substantially equal to the thickness of the cutting blade. The riving knife is positioned in alignment with the cutting blade on the rear side of the cutting blade. The riving knife may enter the kerf during the cutting operation to ensure that the width of the kerf is maintained at more than a predetermined width in order to inhibit unintended contact of the cutting blade with the workpiece. In addition, there has been proposed to provide kickback-inhibiting claws that are disposed on either side of the riving knife within a range so as to not interfere with the movement of the workpiece. The kickback-inhibiting claws are provided in order to inhibit the workpiece from being lifted up. Such techniques are disclosed, for example, in Japanese Laid-open Utility Model Publication No. 3-42602 and U.S. Pat. No. 6,405,624.
Because the claws engage with the upper surface of the workpiece in order to inhibit the kickback phenomenon, some problems have been observed. If a decorative plywood board workpiece were to be cut, in some cases it would be preferable for the kickback-inhibiting claws to not come into contact with the surface of the workpiece in order to inhibit or minimize the possibility of the workpiece being damaged by the claws. In such a case, it is necessary to remove the kickback-inhibiting claws or to move the claws to a position where the claws do not contact the workpiece. However, the known kickback-inhibiting claws have not been designed to take these problems into account. Therefore, the known kickback-inhibiting claws cannot be easily moved and maintained in a position where the claws do not contact the workpiece. In addition, the known claws cannot be easily removed. As a result, it is difficult to practically use a cutting device incorporating kickback-inhibiting claws in order to cut decorative plywood board or the like.